<!DOCTYPE html>
<style>
    #foo {
        width:100px;
        height:100px;
        background-image: -webkit-image-set(url('resources/blue-100-px-square.png') 1x, url('resources/green-400-px-square.png') 2x);
    }
</style>
<script>
    if (window.testRunner)
        testRunner.zoomPageIn();
</script>
<div>This test passes if the div below is a green square.</div>
<div id=foo></div>
